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What is all this S-Parameter Stuff Anyhow?
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+OpenEMS can model a pcb layout well enought to produce S-parameters for things like distributed element filters (aka hairpin filters), traces (useful in signal integrity), and etc. This is exciting because to do these tests on a real life workbench would require a VNA (Vector Network Analyzer)! S-Parameters (Scattering Parameters) descibe the relationship between ports (think test points) in a system. For our first adventure into this we are interested with S11 and S21. S11 is one of the reflection coeficient between port 1 and port 2 meaning the part of the energy sent from port 1 that bounced back. S21 is one of the transmission coefficients meaning the energy sent from port 1 that made it out of port 2.
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+It's about impedances. If your traces or filter don't use them properly waves will can be dissipated or reflected back (often self interfearing) at their source rather than arriving at their distination. For filters the implication is obvious as this is the effect we manipulate to create them. In the case of signal integrity we care about this because it means the signal not only might be "filtered" but worse it might raditate to other near by traces! Using OpenEMS's field dumps that effect can be visualized but that's out of the scope of this pool node.
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+I strongly recommend Lines and Fields in Electronic Technology This is one of the few college textbooks I liked.-EEF
+Keysight have a nice pdf explaining how this all connects to signal integrity.
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+How to begin
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